Great bowerbirds seasonally display vocal signals, physical signals and a unique visual signal, a decorated bower. Bowers, used solely to entice females to mate, are made of twigs and decorated with colored objects. The work proposed will investigate whether perception of colored objects used by male great bowerbirds is categorical or continuous. Categorical perception involves parsing continuous stimuli into categories. Bowerbirds' natural tendency collect colored items offered to them will allow testing of color preference and categorical perception. We will also examine seasonal changes in the volume of nuclei thought to be important in visual memory and perception and nuclei known to be important in vocal control. Examination of steroid receptor distributions will be determined by immunocytochemistry, allowing for interesting comparisons between hormone sensitive neural functions in bowerbirds and other songbirds. This work will not only provide helpful information to aid in currently unsuccessful attempts to breed bowerbirds in captivity but will also expand or current understanding of the way hormones function in cognition. Our understanding of the role that hormones play in normal cognition is rapidly expanding to include vast implications for use of hormones in treating symptoms of cognitive decline in post-menopausal women. Our study is also an initial contribution to the role hormones play in visual perception.